1. Field of the Disclosure
This disclosure generally relates to a human-machine interaction system and, more particularly, to an optical pointing system.
2. Description of the Related Art
The conventional remote controller includes a plurality of press buttons so that a user can press at least one press button thereon to generate a control signal so as to correspondingly control a home appliance. However, the press buttons have limited control functions and thus the pointing system for controlling home appliances by using the images captured by an image sensor is developed.
A pointing system generally includes a plurality of system reference points for being captured by the image sensor, and a processing unit is configured to calculate the position variation, which will be served as a displacement, of reference point images according to the captured images. The displacement is used to correspondingly control a cursor motion.
When receiving an image frame, the processing unit sequentially detects every pixel in the image frame so as to identify whether an object image exists in the image frame or not, and the pixel information associated with the object image is temporarily saved in a buffer. Referring to FIG. 1, for example three object images 91-93 are contained in an image frame 90, wherein the object images 91 and 92 indicate the system reference points and the object image 93 indicates the ambient noise. The processing unit saves the information of all object images 91-93 into the buffer at first and then performs the post-processing, e.g. identifying which of the object images 91-93 is caused by ambient noises.
In the above method, as the data associated with all object images in one image frame is all saved at first, a large memory space will be used such that the buffer having a large memory space is required or the memory space may not be enough in some operating environments, e.g. having many ambient light sources.
Accordingly, the present disclosure further provides an optical pointing device that may real-timely release the occupied memory space of the buffer.